1. Field of the Invention
The present invention relates to installed floors and more particularly, to a new and improved aggregate floor and method for forming same.
2. Description of the Prior Art
Aggregate, particularly terrazzo, floors have been used for many years and have for the most part been constructed in accordance with well-established principles and methods throughout that period of time. Customarily a foundation layer of material usually composed of concrete, which may be formed in any desired thickness according to load requirements, is placed on the ground. A screed bed into which divider strips are usually imbedded is then installed over the foundation layer forming panels into which is poured a mixture of cement, water and aggregate. A screed bed is a mixture of sand, cement and water, labeled a "lean" mixture because it contains no aggregate and less water than the accepted formula for concrete, and is considered an integral part of a terrazzo installation because it brings the foundation substrate layer closer to level, absorbs horizontal movement between the building structure and the aggregate surface, and serves as a setting bed for the panel forming divider strips. The divider strips serve as a gauge as to which the floor will be leveled and provide expansion joints and control paths for cracks.
The resulting floor is quickly trowel-leveled to the top of the strips, if strips are present. After this initial leveling, plain, matching aggregate is sprinkled over the surface which is then compacted and compressed with static rollers varying in size and weight from 2 inches (2") to twenty-four inches (24") in diameter and from two (2) pounds to three hundred (300) pounds in weight. The purpose of this multiple rolling operation is to level the surface, force out any entrapped air and all excess cement, and compact the aggregate to the greatest possible density. Once the mixture cures, it is polished so that the aggregate, usually marble, contained therein becomes decorative and formal in appearance.
Certain problems are encountered in this conventional process. Cement has a limited open time within which the necessary steps must be accomplished to complete leveling and compacting the aggregate before curing begins. When the weight of a static roller is the only factor upon which compression depends, and these rollers must be utilized in multiple directions as well as varying sizes, the time-factor must be apportioned to the steps involved and becomes more critical, diminishing the size of the workable area within the available time. Restricted by the various times involved, it is necessary to pour a limited area of such a floor so that one section can be completed before a new section is started. Consequently the installation process is an involved and extended one.
Thus prior art formation of terrazzo floors is necessarily slow and labor-intensive. Continuing efforts to decrease the time needed for the installation of such floors have been made but without significant success. The present invention is directed to this end, and provides an expediency heretofore unachieved in the art.